powerpc/pseries: Partition hibernation support

Enables support for HMC initiated partition hibernation. This is
a firmware assisted hibernation, since the firmware handles writing
the memory out to disk, along with other partition information,
so we just mimic suspend to ram.

Signed-off-by: Brian King <[e-mail]>
Signed-off-by: Benjamin Herrenschmidt <[e-mail]>

arch/powerpc/Kconfig

···
 config ARCH_SUSPEND_POSSIBLE
 	def_bool y
 	depends on ADB_PMU || PPC_EFIKA || PPC_LITE5200 || PPC_83xx || \
-		   PPC_85xx || PPC_86xx
+		   PPC_85xx || PPC_86xx || PPC_PSERIES
 
 config PPC_DCR_NATIVE
 	bool

arch/powerpc/include/asm/machdep.h

···
 	void (*suspend_disable_irqs)(void);
 	void (*suspend_enable_irqs)(void);
 #endif
+	int (*suspend_disable_cpu)(void);
 
 #ifdef CONFIG_ARCH_CPU_PROBE_RELEASE
 	ssize_t (*cpu_probe)(const char *, size_t);

arch/powerpc/platforms/pseries/Makefile

···
 obj-$(CONFIG_PHYP_DUMP)	+= phyp_dump.o
 obj-$(CONFIG_CMM)		+= cmm.o
 obj-$(CONFIG_DTL)		+= dtl.o
+
+ifeq ($(CONFIG_PPC_PSERIES),y)
+obj-$(CONFIG_SUSPEND)		+= suspend.o
+endif

arch/powerpc/platforms/pseries/hotplug-cpu.c

···
 
 	if (get_preferred_offline_state(cpu) == CPU_STATE_INACTIVE) {
 		set_cpu_current_state(cpu, CPU_STATE_INACTIVE);
+		if (ppc_md.suspend_disable_cpu)
+			ppc_md.suspend_disable_cpu();
+
 		cede_latency_hint = 2;
 
 		get_lppaca()->idle = 1;

arch/powerpc/platforms/pseries/suspend.c

···
+/*
+  * Copyright (C) 2010 Brian King IBM Corporation
+  *
+  * This program is free software; you can redistribute it and/or modify
+  * it under the terms of the GNU General Public License as published by
+  * the Free Software Foundation; either version 2 of the License, or
+  * (at your option) any later version.
+  *
+  * This program is distributed in the hope that it will be useful,
+  * but WITHOUT ANY WARRANTY; without even the implied warranty of
+  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+  * GNU General Public License for more details.
+  *
+  * You should have received a copy of the GNU General Public License
+  * along with this program; if not, write to the Free Software
+  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
+  */
+
+#include <linux/delay.h>
+#include <linux/suspend.h>
+#include <asm/firmware.h>
+#include <asm/hvcall.h>
+#include <asm/machdep.h>
+#include <asm/mmu.h>
+#include <asm/rtas.h>
+
+static u64 stream_id;
+static struct sys_device suspend_sysdev;
+static DECLARE_COMPLETION(suspend_work);
+static struct rtas_suspend_me_data suspend_data;
+static atomic_t suspending;
+
+/**
+ * pseries_suspend_begin - First phase of hibernation
+ *
+ * Check to ensure we are in a valid state to hibernate
+ *
+ * Return value:
+ * 	0 on success / other on failure
+ **/
+static int pseries_suspend_begin(suspend_state_t state)
+{
+	long vasi_state, rc;
+	unsigned long retbuf[PLPAR_HCALL_BUFSIZE];
+
+	/* Make sure the state is valid */
+	rc = plpar_hcall(H_VASI_STATE, retbuf, stream_id);
+
+	vasi_state = retbuf[0];
+
+	if (rc) {
+		pr_err("pseries_suspend_begin: vasi_state returned %ld\n",rc);
+		return rc;
+	} else if (vasi_state == H_VASI_ENABLED) {
+		return -EAGAIN;
+	} else if (vasi_state != H_VASI_SUSPENDING) {
+		pr_err("pseries_suspend_begin: vasi_state returned state %ld\n",
+		       vasi_state);
+		return -EIO;
+	}
+
+	return 0;
+}
+
+/**
+ * pseries_suspend_cpu - Suspend a single CPU
+ *
+ * Makes the H_JOIN call to suspend the CPU
+ *
+ **/
+static int pseries_suspend_cpu(void)
+{
+	if (atomic_read(&suspending))
+		return rtas_suspend_cpu(&suspend_data);
+	return 0;
+}
+
+/**
+ * pseries_suspend_enter - Final phase of hibernation
+ *
+ * Return value:
+ * 	0 on success / other on failure
+ **/
+static int pseries_suspend_enter(suspend_state_t state)
+{
+	int rc = rtas_suspend_last_cpu(&suspend_data);
+
+	atomic_set(&suspending, 0);
+	atomic_set(&suspend_data.done, 1);
+	return rc;
+}
+
+/**
+ * pseries_prepare_late - Prepare to suspend all other CPUs
+ *
+ * Return value:
+ * 	0 on success / other on failure
+ **/
+static int pseries_prepare_late(void)
+{
+	atomic_set(&suspending, 1);
+	atomic_set(&suspend_data.working, 0);
+	atomic_set(&suspend_data.done, 0);
+	atomic_set(&suspend_data.error, 0);
+	suspend_data.complete = &suspend_work;
+	INIT_COMPLETION(suspend_work);
+	return 0;
+}
+
+/**
+ * store_hibernate - Initiate partition hibernation
+ * @classdev:	sysdev class struct
+ * @attr:		class device attribute struct
+ * @buf:		buffer
+ * @count:		buffer size
+ *
+ * Write the stream ID received from the HMC to this file
+ * to trigger hibernating the partition
+ *
+ * Return value:
+ * 	number of bytes printed to buffer / other on failure
+ **/
+static ssize_t store_hibernate(struct sysdev_class *classdev,
+			       struct sysdev_class_attribute *attr,
+			       const char *buf, size_t count)
+{
+	int rc;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EPERM;
+
+	stream_id = simple_strtoul(buf, NULL, 16);
+
+	do {
+		rc = pseries_suspend_begin(PM_SUSPEND_MEM);
+		if (rc == -EAGAIN)
+			ssleep(1);
+	} while (rc == -EAGAIN);
+
+	if (!rc)
+		rc = pm_suspend(PM_SUSPEND_MEM);
+
+	stream_id = 0;
+
+	if (!rc)
+		rc = count;
+	return rc;
+}
+
+static SYSDEV_CLASS_ATTR(hibernate, S_IWUSR, NULL, store_hibernate);
+
+static struct sysdev_class suspend_sysdev_class = {
+	.name = "power",
+};
+
+static struct platform_suspend_ops pseries_suspend_ops = {
+	.valid		= suspend_valid_only_mem,
+	.begin		= pseries_suspend_begin,
+	.prepare_late	= pseries_prepare_late,
+	.enter		= pseries_suspend_enter,
+};
+
+/**
+ * pseries_suspend_sysfs_register - Register with sysfs
+ *
+ * Return value:
+ * 	0 on success / other on failure
+ **/
+static int pseries_suspend_sysfs_register(struct sys_device *sysdev)
+{
+	int rc;
+
+	if ((rc = sysdev_class_register(&suspend_sysdev_class)))
+		return rc;
+
+	sysdev->id = 0;
+	sysdev->cls = &suspend_sysdev_class;
+
+	if ((rc = sysdev_class_create_file(&suspend_sysdev_class, &attr_hibernate)))
+		goto class_unregister;
+
+	return 0;
+
+class_unregister:
+	sysdev_class_unregister(&suspend_sysdev_class);
+	return rc;
+}
+
+/**
+ * pseries_suspend_init - initcall for pSeries suspend
+ *
+ * Return value:
+ * 	0 on success / other on failure
+ **/
+static int __init pseries_suspend_init(void)
+{
+	int rc;
+
+	if (!machine_is(pseries) || !firmware_has_feature(FW_FEATURE_LPAR))
+		return 0;
+
+	suspend_data.token = rtas_token("ibm,suspend-me");
+	if (suspend_data.token == RTAS_UNKNOWN_SERVICE)
+		return 0;
+
+	if ((rc = pseries_suspend_sysfs_register(&suspend_sysdev)))
+		return rc;
+
+	ppc_md.suspend_disable_cpu = pseries_suspend_cpu;
+	suspend_set_ops(&pseries_suspend_ops);
+	return 0;
+}
+
+__initcall(pseries_suspend_init);